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Ephemeris: 06/06/2025 – GTAS meeting tonight

June 6, 2025 Comments off

This is Bob Moler with Ephemeris for Friday, June 6th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57. The Moon, 4 days past first quarter, will set at 3:32 tomorrow morning. | The Grand Traverse Astronomical Society will host its May meeting tonight at 9 PM at Northwestern Michigan College’s Joseph H Rogers Observatory. The talk for the evening is a mystery to me, and I’m the Newsletter Editor. However, since I’ve given more programs than any other to the group, I will have a presentation old or new, if the need arises. After the meeting, around 10 PM, weather permitting, there will be viewing of the Moon and whatever we can find in the twilight. The observatory is located south of Traverse City on Birmley Rd. The meeting will also be available via Zoom. Instructions will be on the society’s website, gtastro.org.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Joseph H. Rogers Observatory of Northwestern Michigan College, meeting place of the Grand Traverse Astronomical Society, Traverse City, Michigan.
Joseph H. Rogers Observatory of Northwestern Michigan College, meeting place of the Grand Traverse Astronomical Society, Traverse City, Michigan.
Categories: Ephemeris Program, GTAS Outreach Event Tags:

Ephemeris: 06/05/2025 – The free planetarium program I use

June 5, 2025 Comments off

This is Ephemeris for Thursday, June 5th. Today the Sun will be up for 15 hours and 26 minutes, setting at 9:24, and it will rise tomorrow at 5:58. The Moon, 3 days past first quarter, will set at 3:14 tomorrow morning.

Due to my physical shortcomings, which started about five years ago, I’m not able to get out under the stars as much as I used to. My observing is basically confined to star parties that the Grand Traverse Astronomical Society hosts. Most of my “observing” is done using a planetarium program called Stellarium. It is, to my mind, the best and most accurate portrayal of the heavens of the planetarium programs that I’ve seen, and it’s free and open source! It can be downloaded from the Internet for computers: Windows, Macs, and Linux from stellarium.org. A web based version, which you don’t even have to download, is stellarium-web.org. There’s also versions for Android smartphones, iPhones and tablets.

    Addendum

    A view of the sky looking up and southeastward using Stellarium.
    A view of the sky looking up and southeastward using Stellarium. I clicked on the star Arcturus and information on it is shown on the left. It is more informatiom that I usually need. Many of the images I create use Stellarium as the base component. For the images I create for the blog, I acknowledge the free apps used to create them. Click or tap on the image to enlarge it.
    The January 24, 1925 total solar eclipse that was visible in Traverse City, recreated using Stellarium.
    The January 24, 1925 total solar eclipse that was visible in Traverse City, recreated using Stellarium. See that post here. I used one of the supplied landscapes, when showing morning planets that are visible relatively close to the Sun in the winter.
    Categories: Astronomical Software, Ephemeris Program Tags: ,

    Ephemeris: 06/04/2025 – Taking our weekly look at where the naked-eye planets have wondered off to

    June 4, 2025 Comments off

    This is Ephemeris for Wednesday, June 4th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 2 days past first quarter, will set at 2:57 tomorrow morning.

    Let’s take our weekly look at the whereabouts of the naked-eye planets. At 10 PM this evening two naked eye planets will be out. Jupiter, is then very low on the west-northwestern horizon, difficult or impossible to find. Fading Mars, with its distinctive reddish hue, is in the west-southwest, at that time, though better seen when the skies are darker. It’s slowly approaching the bright star Regulus in Leo the lion, which it will pass on June 16th. By 5 AM Venus will be seen very low in the east, as the Morning Star, with Saturn to the right in the east-southeast and above it. Venus will be visible until close to 5:40. For those with telescopes, Saturn’s rings are now slowly opening up again, and will for the next 7 years.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    Though Mercury and Jupiter are still in the evening sky, they are too close to the Sun to really be visible. Only Mars is left. It is approaching the star Regulus, which it will pass just north of on the 16th. The waxing gibbous Moon is entering Virgo tonight. Created using LibreOffice Draw, and GIMP.
    The Moon tonight, June 4, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
    Venus and Saturn at 5 AM tomorrow morning, June 5th, 2025, low in the east
    Venus and Saturn at 5 AM tomorrow morning, June 5th, 2025, low in the east. Created using Stellarium.
    Telescopic Saturn and Venus as they would be seen in a small telescope with the same magnification
    Telescopic Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification. Mars is 5.4″ in diameter, too small to be shown here. My lower size limit is 10″. On the morning of the 5th, Saturn is 16.9″ in diameter, but its rings, being nearly edge on should show up brighter than seen here., and extend to 39.5″. They are tlted 3.2° from being edge on. Venus’ apparent diameter is 22.7″, and is 51.8% iluminated. The ” means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
    The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on June 4, 2025
    The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on June 4, 2025. The night ends on the left with sunrise on the 5th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
    A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, June 4th and 5th, 2025
    This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, June 4th and 5th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.
    Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

    Ephemeris: 06/03/2025 – Looking at the Moon tonight

    June 3, 2025 Comments off

    This is Bob Moler with Ephemeris for Tuesday, June 3rd. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 1 day past first quarter, will set at 2:41 tomorrow morning.

    For me, the best time to view the Moon with binoculars or a telescope is around first quarter and tonight’s Moon is just a day past first quarter. At this time we see the maximum amount of shadowing of the craters because the sunrise line which we call the terminator is cutting across, pretty much, the center of the Moon. Since the Moon is a pretty uniformly dark gray with light gray areas, shadows make all the difference in seeing detail. One thing to notice on tonight’s Moon is that the southern or bottom part of the Moon has a lot of craters and is bright gray. This is called the lunar highlands and is brighter than the darker areas to the north and on the western side of the Moon, which are covered by the maria or seas, plains of solidified lava flows.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    The Moon as it might appear tonight, June 3rd 2025, in a low power telescope. Selected features are marked. Created using Stellarium, LibreOffice Draw and GIMP.

    Translations of some lunar feature names according to Virtual Moon Atlas

    Lacus Mortis – Lake of Death
    Lacus Somniorum – Lake of Dreams
    Mare Crisium – Sea of Crises
    Mare Fecunditatis – Sea of Fruitfulness
    Mare Frigoris – Sea of Cold
    Mare Imbrium – Sea of Showers
    Mare Nectaris – Sea of Nectar
    Mare Serenitatis – Sea of Serenity
    Mare Tranquillitatis – Sea of Tranquility
    Mare Vaporum – Sea of Vapors
    Montes Alpes – Alps Mountains
    Montes Apenninus – Apennines Mountains
    Sinus Asperitatis – Bay of Roughness
    Sinus Medii – Central Bay

    Note: Mare is pronounced Mar-e, and Maria is pronounced Mar-e-a.

    These features, for the most part, were named by Giovanni Battista Riccioli in 1651, when he produced the first accurate map of the Moon. Craters are named for persons, real or otherwise. Features like Seas, Lakes and Bays were given fanciful names. Labels are centered on their feature where possible.

    Categories: Ephemeris Program, Observing, The Moon

    Ephemeris: 06/02/2025 – 50th anniversary: What’s an ephemeris anyway?

    June 2, 2025 1 comment

    This is Ephemeris for Monday, June 2nd. Today the Sun will be up for 15 hours and 22 minutes, setting at 9:22, and it will rise tomorrow at 5:59. The Moon, at first quarter today, will set at 2:25 tomorrow morning.

    Today I embark on the Ephemeris program’s 51st trip around the Sun. The purpose of this program is more than giving the sunrise and sunset times, which was the station’s original request. Nowadays, one can get that from the weather app on a smartphone much more accurately than I can. From the beginning I’ve included some fact of astronomy or something visible in the sky with the naked eye or at least find to it using the naked eye stars as a guide, and visible in binoculars. That is the essence of this program. The title Ephemeris comes from the Greek and Latin meaning diary or journal. In astronomy, it is a tabular list of planet, asteroid or comet positions, as they change with time.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    Today we'd call this a selfie, with me and the equipment I hauled out to Prince Edward Island for the July 10th, 1972 total solar eclipse.
    Today we’d call this a selfie, with me and the equipment I hauled out to Prince Edward Island for the July 10th, 1972 total solar eclipse. This was three years before the Ephemeris program started. This was my third successful total solar eclipse out of three tries. I was to witness and report on three more total solar eclipses, and two annular eclipses during the run of the Ephemeris program.
    This photograph of the diamond ring at the end of totality is my favorite.
    I’ve gotten many photographs of this eclipse. This is the first time that my photographic equipment actually worked properly. The images of the Sun’s corona were great, however this photograph of the diamond ring at the end of totality is my favorite.

    Categories: Ephemeris Program, Inside Ephemeris

    Ephemeris: 05/30/2025 – Ending orbit 50, looking ahead to the 1st month of orbit 51

    May 30, 2025 Comments off

    This is Bob Moler with Ephemeris for Friday, May 30th, the last program of Ephemeris’ 50th orbit of the Sun. Today the Sun will be up for 15 hours and 18 minutes, setting at 9:19, and it will rise tomorrow at 6:00. The Moon, 3 days before first quarter, will set at 1:17 tomorrow morning.

    Let’s take a look at June skies. There will be a lot of sunshine this month. The daylight hours will increase a bit from 15 hours and 21 minutes today to 15 hours and 34 minutes on the 21st, retreating back to 15 hours 31 minutes at month’s end. At this time of the year the sunset times for Ludington, Interlochen, Petoskey and Mackinaw City are very nearly the same. However, the sunrise times are at their most divergent. With Ludington’s sunrise being 14 minutes later than Mackinaw City’s. The altitude of the Sun above the southern horizon at local noon (1:44 pm in Interlochen) on the solstice, June 20th will be 68 and three-quarters degrees. Summer will start at 10:42 PM that night.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    June Evening Star Chart

    Star Chart for June 2024 (11 p.m. EDT, June 15, 2024)
    Star Chart for June 2025 (11 p.m. EDT, June 15, 2025). Created using my LookingUp program. Click or tap on the image to enlarge it.

    The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4 a.m. for the morning chart. These are the chart times. Note that Interlochen/Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
    Note, the chart times of 11 p.m. and 4 a.m. are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour, or 28 minutes. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog for weekly positions.

    June Morning Star Chart

    Star Chart for June mornings, 2024 (4 am EDT, June 15, 2024)
    Star Chart for June mornings, 2025 (4 am EDT, June 16, 2025). Created using my LookingUp program. Click or tap on the image to enlarge it.

    For a list of constellation names to go with the abbreviations, click here.

    • Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
    • Leaky dipper drips on Leo
    • Follow the arc of the handle of the Big Dipper to the star Arcturus, and
    • Extend like a spike to Spica,

    Twilight Limits, Nautical and Astronomical

          EDT        
      Morning Twilight Evening Twilight Dark Night Moon
    Date Astro. Nautical Nautical Astro. Start End Illum.
    2025-06-01 3h39m 4h38m 22h47m 23h46m 1h45m 3h39m 0.41
    2025-06-02 3h38m 4h37m 22h48m 23h48m 2h07m 3h38m 0.51
    2025-06-03 3h37m 4h37m 22h49m 23h49m 2h26m 3h37m 0.60
    2025-06-04 3h36m 4h36m 22h50m 23h51m 2h42m 3h36m 0.70
    2025-06-05 3h35m 4h35m 22h51m 23h52m 2h58m 3h35m 0.78
    2025-06-06 3h34m 4h35m 22h52m 23h53m 3h14m 3h34m 0.85
    2025-06-07 3h33m 4h34m 22h53m 23h55m 3h33m 3h33m 0.91
    2025-06-08 3h32m 4h34m 22h54m 23h56m – – 0.96
    2025-06-09 3h31m 4h33m 22h55m 23h57m – – 0.99
    2025-06-10 3h30m 4h33m 22h55m 23h58m – – 1.00
    2025-06-11 3h30m 4h33m 22h56m 23h59m – – 0.99
    2025-06-12 3h29m 4h32m 22h57m 0h00m – – 0.96
    2025-06-13 3h29m 4h32m 22h58m 0h01m – – 0.92
    2025-06-14 3h28m 4h32m 22h58m 0h02m – – 0.85
    2025-06-15 3h28m 4h32m 22h59m 0h03m 0h03m 0h30m 0.77
    2025-06-16 3h28m 4h32m 22h59m 0h03m 0h03m 0h55m 0.68
    2025-06-17 3h28m 4h32m 23h00m 0h04m 0h04m 1h17m 0.57
    2025-06-18 3h28m 4h32m 23h00m 0h04m 0h04m 1h36m 0.46
    2025-06-19 3h28m 4h32m 23h00m 0h05m 0h05m 1h56m 0.34
    2025-06-20 3h28m 4h32m 23h00m 0h05m 0h05m 2h16m 0.24
    2025-06-21 3h28m 4h32m 23h01m 0h05m 0h05m 2h39m 0.14
    2025-06-22 3h28m 4h33m 23h01m 0h05m 0h05m 3h07m 0.07
    2025-06-23 3h29m 4h33m 23h01m 0h05m 0h05m 3h29m 0.02
    2025-06-24 3h29m 4h33m 23h01m 0h05m 0h05m 3h29m 0.00
    2025-06-25 3h30m 4h34m 23h01m 0h05m 0h05m 3h30m 0.01
    2025-06-26 3h30m 4h34m 23h01m 0h05m 0h05m 3h30m 0.04
    2025-06-27 3h31m 4h35m 23h01m 0h05m 0h05m 3h31m 0.10
    2025-06-28 3h32m 4h35m 23h01m 0h04m 0h04m 3h32m 0.17
    2025-06-29 3h33m 4h36m 23h00m 0h04m 0h09m 3h33m 0.26
    2025-06-30 3h34m 4h37m 23h00m 0h03m 0h29m 3h34m 0.35

    The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some modifications. See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

    NASA Calendar of Planetary Events

       Date       Time    Event 
Jun  1  Su            Venus: 45.9° W
     1  Su   5:49 AM  Moon-Mars: 1.5° S
     1  Su   9:30 PM  Moon-Regulus: 1.9° S
     2  Mo  11:41 PM  First Quarter
     3  Tu   9:33 PM  Moon Descending Node
     6  Fr  10:15 AM  Moon-Spica: 0.6° N
     7  Sa   6:42 AM  Moon Apogee: 405600 km
    10  Tu   6:25 AM  Moon-Antares: 0.3° N
    11  We   3:44 AM  Full Moon
    11  We   7:54 PM  Moon South Dec.: 28.4° S
    16  Mo  10:05 PM  Mars-Regulus: 0.7° N
    18  We   5:41 AM  Moon Ascending Node
    18  We   3:19 PM  Last Quarter
    18  We  11:47 PM  Moon-Saturn: 3.4° S
    20  Fr  10:42 PM  Summer Solstice
    21  Sa   3:51 PM  Mercury-Pollux: 5° S
    22  Su  10:59 PM  Moon-Pleiades: 0.6° S
    23  Mo  12:43 AM  Moon Perigee: 363200 km
    24  Tu  11:06 AM  Jupiter Conjunction
    24  Tu   9:43 PM  Moon North Dec.: 28.4° N
    25  We   6:31 AM  New Moon
    27  Fr   2:02 AM  Moon-Mercury: 2.9° S
    27  Fr   1:42 PM  Moon-Beehive: 2.1° S
    29  Su   6:26 AM  Moon-Regulus: 1.6° S
    29  Su   9:05 PM  Moon-Mars: 0.2° S
    30  Mo  11:46 PM  Moon Descending Node

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

    Sun and Moon Rising and Setting Events

    LU       Ephemeris of Sky Events for Interlochen/Traverse City, MI
    June, 2025    Local time zone: EDT
    +-----------------------------------------------------------------------+
    | DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
    |      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
    +=======================================================================+
    |Sun  1| 06:00a  09:21p  15:21 | 10:45p  04:37a |      Set  02:07a   38%|
    |Mon  2| 05:59a  09:22p  15:22 | 10:46p  04:36a |F Qtr Set  02:25a   48%|
    |Tue  3| 05:59a  09:23p  15:23 | 10:47p  04:35a |      Set  02:41a   58%|
    |Wed  4| 05:58a  09:23p  15:25 | 10:48p  04:34a |      Set  02:57a   68%|
    |Thu  5| 05:58a  09:24p  15:26 | 10:49p  04:34a |      Set  03:14a   76%|
    |Fri  6| 05:58a  09:25p  15:27 | 10:50p  04:33a |      Set  03:32a   84%|
    |Sat  7| 05:57a  09:26p  15:28 | 10:51p  04:33a |      Set  03:53a   90%|
    +------+-----------------------+----------------+-----------------------+
    |Sun  8| 05:57a  09:26p  15:29 | 10:51p  04:32a |      Set  04:20a   95%|
    |Mon  9| 05:57a  09:27p  15:30 | 10:52p  04:32a |      Set  04:53a   98%|
    |Tue 10| 05:57a  09:27p  15:30 | 10:53p  04:31a |      Set  05:36a  100%|
    |Wed 11| 05:56a  09:28p  15:31 | 10:54p  04:31a |Full  Rise 10:31p   99%|
    |Thu 12| 05:56a  09:29p  15:32 | 10:54p  04:31a |      Rise 11:20p   97%|
    |Fri 13| 05:56a  09:29p  15:32 | 10:55p  04:30a |      Rise 11:59p   93%|
    |Sat 14| 05:56a  09:29p  15:33 | 10:55p  04:30a |      Rise 12:30a   87%|
    +------+-----------------------+----------------+-----------------------+
    |Sun 15| 05:56a  09:30p  15:33 | 10:56p  04:30a |      Rise 12:55a   79%|
    |Mon 16| 05:56a  09:30p  15:34 | 10:56p  04:30a |      Rise 01:17a   69%|
    |Tue 17| 05:56a  09:31p  15:34 | 10:57p  04:30a |      Rise 01:36a   59%|
    |Wed 18| 05:56a  09:31p  15:34 | 10:57p  04:30a |L Qtr Rise 01:55a   48%|
    |Thu 19| 05:56a  09:31p  15:34 | 10:58p  04:30a |      Rise 02:15a   37%|
    |Fri 20| 05:57a  09:31p  15:34 | 10:58p  04:30a |      Rise 02:38a   26%|
    |Sat 21| 05:57a  09:32p  15:34 | 10:58p  04:30a |      Rise 03:07a   16%|
    +------+-----------------------+----------------+-----------------------+
    |Sun 22| 05:57a  09:32p  15:34 | 10:58p  04:31a |      Rise 03:44a    9%|
    |Mon 23| 05:57a  09:32p  15:34 | 10:58p  04:31a |      Rise 04:33a    3%|
    |Tue 24| 05:58a  09:32p  15:34 | 10:58p  04:31a |      Rise 05:36a    0%|
    |Wed 25| 05:58a  09:32p  15:34 | 10:58p  04:32a |New   Set  10:28p    1%|
    |Thu 26| 05:58a  09:32p  15:33 | 10:58p  04:32a |      Set  11:12p    3%|
    |Fri 27| 05:59a  09:32p  15:33 | 10:58p  04:33a |      Set  11:44p    8%|
    |Sat 28| 05:59a  09:32p  15:32 | 10:58p  04:33a |      Set  12:08a   15%|
    +------+-----------------------+----------------+-----------------------+
    |Sun 29| 06:00a  09:32p  15:32 | 10:57p  04:34a |      Set  12:28a   24%|
    |Mon 30| 06:00a  09:32p  15:31 | 10:57p  04:35a |      Set  12:46a   33%|
    +-----------------------------------------------------------------------+
    * Nautical Twilight
    ** Moonrise or moonset, whichever occurs between sunset and sunrise

    Generated using my LookingUp for DOS app.

    Categories: Ephemeris Program, Month preview Tags:

    Ephemeris: 05/29/2025 – Finding the celestial dragon

    May 29, 2025 Comments off

    This is Ephemeris for Thursday, May 29th. Today the Sun will be up for 15 hours and 17 minutes, setting at 9:19, and it will rise tomorrow at 6:01. The Moon, 3 days past new, will set at 12:40 tomorrow morning.

    High in the northern sky at 11 p.m. lies the twisted constellation of Draco the dragon. This dragon is more like the snakelike dragon of the Chinese New Year parades than the dinosaur-like dragon of European legend. I find it better to start at the tail of Draco, to trace him out in the stars. Draco’s tail ends between the Big and Little Dippers high in the north-northwest. The Dragon is seen in a line of stars that extends parallel to the handle of the Big Dipper before curving around the bowl of the Little Dipper then bends back down to the level of Polaris in the north-northeast before turning toward the east. The head of Draco is an odd box of stars near the bright star Vega, in the east. Though not made up of very bright stars, Draco has an easy shape to trace.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    A Finder for Draco the dragon. Looking high in the northeast Draco can be seen. Its tail is between the Big and Little Dippers, and its head is north of the bright star Vega in Lyra the harp. According to Greek myth when the dragon was sent to attack the goddess Athena she was able to defeat it and threw it up into the sky where it got tangled with the axis of the heavens. Polaris is our current pole star, pointed to by the North Pole of the Earth’s axis. Around 2800 BCE the dim star Thuban in Draco was the pole star.
    Categories: Constellations, Mythology, Observing Tags:

    Ephemeris: 05/28/2025 – Our weekly look at the whereabouts of the naked-eye planets

    May 28, 2025 Comments off

    This is Ephemeris for Wednesday, May 28th. Today the Sun will be up for 15 hours and 15 minutes, setting at 9:18, and it will rise tomorrow at 6:01. The Moon, 2 days past new, will set at 11:50 this evening.

    Let’s take our weekly look at the whereabouts of the naked-eye planets. At 10 PM this evening two naked eye planets will be out. Jupiter, is now low in the west-northwestern sky Underneath the waxing crescent Moon. The fading Mars, with its distinctive reddish hue, is in the west-southwest, at that time. It’s slowly approaching the bright star Regulus in Leo the lion, which it will pass on June 16th. By 5 AM Venus will be seen very low in the east, as the Morning Star, with Saturn to the right and a bit above it. Venus will require a low eastern horizon then. But it will rise and be visible until close to 5:45. For those with telescopes, Saturn’s rings are now open­ing up again, and will for the next 7 years.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    The evening planets Jupiter and Mars seen with the fading stars of winter in bright twilight at 10 PM
    The evening planets Jupiter and Mars seen with the fading stars of winter in bright twilight at 10 PM, tonight May 28th, 2025. It looks like the last chance to see Jupiter in the evening sky until late fall. Created using Stellarium and GIMP.
    Venus and Saturn at 5 AM tomorrow morning
    Venus and Saturn at 5 AM tomorrow morning, May 29th, 2025, low in the east. Created using Stellarium.
    Telescopic Jupiter, Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification
    Telescopic Jupiter, Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification. Jupiter is shown for tonight, 10 PM, May 21, 2025. Its apparent diameter is 32.4″, though its moons will be probably washed out by the bright twilight. Mars is 5.6″ in diameter, too small to be shown here. My lower size limit is 10″. Saturn is shown on the morning of the 29, it is 16.8″ in diameter, but its rings, being nearly edge on should show up brighter than seen here., and extend to 39.0″. They are 3.1° from being edge on. Venus’ apparent diameter is 24.6″, and is 47.6% iluminated. Planetary surface detail is more subtle than shown here. The ” means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts).
    The naked-eye planets and the Moon at sunset and sunrise on a single night
    The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on May 28, 2025. The night ends on the left with sunrise on the 29th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
    This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, May 28th and 29th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.

    Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

    Ephemeris: 05/27/2025 – The many faces of the Big Dipper

    May 27, 2025 Comments off

    This is Ephemeris for Tuesday, May 27th. Today the Sun will be up for 15 hours and 13 minutes, setting at 9:17, and it will rise tomorrow at 6:02. The Moon, 1 day past new, will set at 10:44 this evening.

    The Big Dipper is overhead, actually north of overhead this evening when it gets dark for us in Michigan, it’s seven stars shining brightly. The Big Dipper is not an actual constellation, recognized internationally. It’s part, the hind part, of Ursa Major, the great bear. The Big Dipper is an asterism or informal constellation. It is a distinctly North American constellation. For fugitive slaves, fleeing the southern states in the days before the Civil War, the Drinking Gourd, as they called it, showed the direction north to freedom. In England the dipper stars become the Plough (plow), or Charles’ Wain (Charlemagne’s Wagon). In France, known for culinary delights it is the saucepan, or the cleaver. Many cultures saw what was familiar to them in these seven bright stars.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    Cultural views of the Big Dipper as an Animation
    Cultural views of the Big Dipper as an animation. Created using my LookingUp app and GIMP.
    Categories: Asterism, Cultures, Ephemeris Program Tags: , , , ,

    Ephemeris: 05/26/2025 – About globular star clusters

    May 26, 2025 Comments off

    This is Ephemeris for Memorial Day, Monday, May 26th. Today the Sun will be up for 15 hours and 12 minutes, setting at 9:16, and it will rise tomorrow at 6:03. The Moon is new today, and won’t be visible.

    The constellation Hercules, out in the evening sky now, contains the brightest globular star cluster in the northern sky. A globular star cluster, about 25 thousand light years away. It’s an ancient assemblage of hundreds of thousands to millions of stars in a big ball. About 150 of these star clusters, that we know of, exist in the Milky Way. They form a spherical distribution around the Milky Way concentrated towards the center. The ages of these clusters runs to over 10 billion years. It is thought that they formed first out of the gas of the Milky Way and so did not participate in the collapse of the gas into the disk of the Milky Way we know today from which later stars were formed. We see them in other galaxies.

    The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

    Addendum

    M13 Great Globular Cluster in Hercules
    M 13 or Messier 13, the Great Hercules Globular Star Cluster, contains hundreds of thousands of stars, and is located around 25 thousand light years away. It is the finest globular cluster in the northern sky. Credit: Daniel Dall’Olmo, Grand Traverse Astronomical Society member.

    Categories: Concepts, Ephemeris Program, Star Cluster Tags: ,